Die-milling machine



Y Jam. 16, 1923.

f LMMM 0. S. LEE. DI E Ml u. NG MAcHmE. F: LED JUNE `27. 1921 l H SHEETS-SHEET l |||||||mum` Y mmuum ummm Jan# 16, 1923.

, II,4I4I2,4I84I 0. S. LEE. DIE MILLING MACHINE. e FILED JUNE 27. i921. l Il SHEETS-SHEET 3 u I ff I )2mm Mum REI-.IE

A i I IIMIIM.l .d5 i

Jan. 16, 1923. 11,442,434

0. S. LEE. DIE MlLLlNG MACHINE. F1 LED JUNE 27, 1921 l l SHEETS-SHEET 4 Il SHEETS-SHEET 5 Jan. 16, E923.

0. S. LEE.

DIE MILLING MACHINE. FILED JUNE 27. 1921.

MII

O. S, LEE. DIE MILLING MACHINE Fl LED JUNE 27. 1921 Jan. 16,1923.

H SHEETS-SHEET 8 Jan. 16, 1923. LMA-2,484

0. S..LEE.

` DIE MILLING MAcHxNE.

AFILED JUNE 27, 1921. ll SHEETS-SHEET 9 Jan. 16, 1923. 1. 0. S. LEE.

DIE MILLING MACHINE. FILED JUNE 27. 1921. SHEETS-SHEET ll 0 Patented dan. l5, 19.23.

OTTAB S. LEE, OF CHICAGO, LLINGS, SSIG'NOR .CO NYE TUOI, AND MACHENE GRKS, 0F CHICAG. ILLIEUES, A CORFDEATN OF IL'AJINGIT'.

DIE-tirannie Maestrias.

Application filed June 27, 1921.

To @ZZ wiwi/'i i# may concer/n Be it known that I. U'r'ran b3. zen ot the Lfmted States, residi. L

Liuc. a citiat Chicago. in the countT ot @ook and tritate olf Illinois, have invented a new and use'tul Ylmprovement in Die-Milling ll/lachines, ot which the following is a specilication.

My invention relates, more particularly, to the cutting of threads on dies, and esl:- pecially to machines wherein provision is made tor producing' the desired threads in backed oil, or relieved7 condition; and nay primary objects, generally stated. are to provide a novel, simple and, positively-operating construction ot means for etlecting the backing-oft177 of the threads.. and to cause the dies produced to be unit'orm and present the internal contour at the threads thereof. best adapted to the accurate torination ot' threads cut by the die; and other objects as will be manifest from the following' description.

Iv have devised my invention 'for embodiment7 more particularly, though not to the exclusion of its embodiment in other constructions ot machines. in machines ot the general construction illustrated and described in my pending; application for United.v ,States Patent. Serial No. F... liled July '1.9. 1920. and have therefore chosen to illustrate it in such a constriufi:ionV ot machine.

Referring to the accomoanying drawings:

F igure l is a View in side elevation ot machine in which my improvements. constructed in accordance with one ot the enibodiments ot' luv invention7 are incorporated. Figure 2 is an enlarged plan view ot' the die-blanl-holding mechanism and the means whereby the desired relative movement. et the die-blank and the milling device. is et fecterd. Figure is a View in end elevation of the mechanism shown in Fig'. 2. the latter being viewed inthe direction ci" the arro'.'.' in 2. Figure 4 is a view in elevation ot the opposite end of the mechanism oi" 2. F igure 5 is a view. in side elevation oil the mechanism oit Fig. 2. with a certain part ot the housing' broken awatT to disclose an interior detail, with the lowermost member shown in perspective. Figure 6 is a` section taken at the line 6 .6 on 2 and viewed serial No. 480,614.

in the direction ot the arrows. the lowermost member also being' shown in perspective. Figure ).7 is a plan View with one oi" 'the parts shown in section and parte broken away, el. the mechanism at the right hand side oit F ig. 5. Figure 8 is a section talien at the irregular line 8 8 on Fig. (i and viewed in the direction oit the arrows. Figure 9 is a plan sectional "View taken through the mechanism for returning the work-holder 'to normal position. F igure l0 is a broken section taken at the irregular `line lO--li on Fig'. o and viewed in the direction olf the arrows. .Figure lll is a section taken at the irregular line ll-ll on Fig. 3 and viewed in the direction of the arrows. F igure l2 is a tace Viewj with certain parts broken away, and in the nature oif a diagram. oit the iuechanisni Vtor shitting the structure supporting` the dieblank, to eilect the backing` ott ot the threads, the parts shown being viewed in the direction of the arrow in 2 and being shown in one of the positions it assumes during the cutting ot the threads. Figure lis a similar view showing' the mechanisni in the position it assumes followingthe threadcutting movement. Figure lll is a 'view likel F 2 ot another or the many forms in which my invention may be provided, Figure lo is a view lilze Fir. .ueture shown in Fig. ifi- Figure lo is a View like Vl2 oi the mechanism ot Figs. lll: and whereby the backing oll' ot the threads effected, this mechanism beinel shown in the position it assumes during' the cutting` o'i the thread; and Figure l?, a View like Fig. lo showing a position assumed by the backing' off i mechanism 'following' the cutting of the thread.

rThe particular construction of machine illustrated is designed for use in the producing' ot threads on die-blanks oit a type commonly lrno'- n.. and formed of an irregularlyshaped body of steel `with a opening therethi-f i into which lug-portions. which form the t read segnnents. when threaded. extend, such a blanl beine' shown in Fig. l() wherein A sented at. 25.y the opening' therein lbeing` shown at 26 and the lug-portions referred to at 27. there being` Yfour of these lug-portions in the particular construction et blank shown. the inner surface of each of which is to be threaded to form the cutting portions of the die, these lug-portions being equidistantly spaced about the opening 26 in the blank, though it will be understood from the following that the invention is not limited to use in the manufacture of the particular form of die shown.

The milling device and work-holding device are mounted on a bed, the work-holding device preferably to be movable lengthwise of the milling device, such a bed, and which is common in lathe constructions, being indicated at 2S upon which a carriage, forming a part of the work-holding device and represented at 29 and extending transversely of the bed,is mounted to slide lengthwise lof the bed, the latter, in practice, being provided with means, such as, for example, those .omrnonly used in lathes -for shifting the tool-holder thereof, for moving the carriage 29 lengthwise of the bed and the milling device 31 the spindle of which, represented at 300, is secured at one end in the head-stock 30, to be rapidly rotated thereby, and journaled at its opposite end in a tailstoclr (not shown) on the bed 28, the mill.- ing device extending through the u'f'orlg-holding device and its operating mechanism supported on the carriage 29 and hereinafter described.

Mounted on the carriage to extend transversely of the bed 28 is a base 32, there being provided between this member and the carriage 29 guiding means for causing the base member 32 to move in a predetermined path crosswise of the bed when adjusted thereon, for the purpose hereinafter explained. The guide-means shown comprise a dovetailed rib 33 provided on the upper surface of the carriage 29 and extending into a dovetailed channel in the bottom of the base longitudinally of thc latter, the rib 33 being disposed at a right ano'le to the axis about which the millingl device 31 carried by the spindle 300 rotates, for a purpose hereinafter explained. The channel 34 also contains a gib 35 cooperating with setscrews (not shown) for rigidly holding the base 32 on the carriage 29 in position of adjustment thereon, effected by means of any suitable device. as for example that commonly used on the tool-holders of lathes for adjusting the tools toward and away from the work and including a depending lug 37 on the member 34 in which a screw shaft (not shown) provided on the carriage 28, and equipped with a hand wheel 38. screws, The upper surface of the base is provided with a dovetailed rib 39 extending lengthwise thereof and crosswise of the bed at an angle slightly oblique to the axis about which the milling` devine 31 rotates, the rib 39 being located within -a dovetailed channel 40 provided in the bottom surface of a sub-base member 41 which also extends crosswise of the bed and is adapted to slide, guided by the rib 39, on the base The sub-base 41 is provided adjacent its opposite ends with upwardly-extending bosses 42 through which a shaft vrterufls, this shaft also extending through pairs of lugs 44 depending fromV the base 45 of a housing inember 46, and through the medium of which shaft the housing member 46 and the parts carried thereby are pivotally connected with the sub-base 41 adapting the said housing, with its several parte, to be tipped in a vertical plane. The edge portion of the base 45 opposite that equipped with the lugs 44, provided with adjustable stop devices shown as screws 4T threaded in the base-portion 45 and bearing at their lower ends against the upper surface of the sub-base 41, the adjustment thus provided permitting of the setting of the base portion 45 at any desired angle relative to the horizontal plane, the baseportion 45 being also provided withscrews 43 which extend outwardly therethrough and screw at their lower ends into threaded openings 4S) :in the sub-base 41 thereby cooperating with the adjusting screws 47 to firmly secure the base-portion 45 in adjusted position. While the member 46 is shown as extending vertically, in use this last-referred-to member would be tipped to the right in Fig. 6, ou the hinge 453, and set in such position by the screws 47 and 48 to extend at an oblique angle to the axis of the milling device, for the purpose hereinafter described. I

The housing portion 46 is formed with an inwardly-extending annular flange 50 which is threaded at its inner periphery, as indicated at 51 (Fig. 6). to present a thread havingl the same pitch as that of the segmental threads to be formed on the dieblank, the thread 51 forming a lead-screw for cooperation with that part of the structure on which the die-blank is held, the parts described being preferably so proporitoned and positioned as shown, as to cause the axis of the milling cutter 31 to extend midway between the upper and lower portions of the bore in the housing member 46. Located within the housing 46 is a rotatable hollow member 52 of circular shape in cross-section threaded between its ends, as indicated at 53, at which thread it screws into the thread 51. At one side of its threaded port-ion 53 the member 52 is equipped with a gear 54 which extends into a. recess 55 in the housing 46, this end of the member 52 extending at a reduced portion 56 thereof. outwardly through `the housing 46, the latter containing' in a face thereof an annular recess 57 in whicha removable ring` 58, secured in place by screws 59, is located, this ring' extending relatrl into the n.

overlapping position fifi, The ou -ii end f. .s annularly 'recessedv if Y y and o; a plate 6l secure-il to the nicmber 2t by means ot the screws o27 thi,I plate (il constituting` a part oli' the mechanism for holding` in place the die-blank to be cut. The opposite end ot the member 52, and represented at Gili, is surrminded bjf .a tubular member (ill in which the member 52 may be rota-ted `except when clutched thereto as hereinafter described. The tube member Gl extends through-the opening in a ring 66 mounted in an annular recess 6i' in the end et the housi i6 opposite that containingv the recess 5i 1nd secured therein by the screws 68, the outwarill}.fextending end or" the member 64 having secured thereon, as at the threaded connection 697 a ring` 70 containing an annulairecess 'Tl in its inner tace. The member (El constitutes one elemei'it ot a clutch de v.ice through the medium ot which lthe member o2 is rotated in the housing fi-(S, the member 6l to this end containingv in a 'tace thereot. that which is disposed at the right hand side Fig'. 5, pa-irs oit' notches 72, preterably diametricaily opposed, these notches cooperating with pairs of lugs 73 also diametricall;7 opposed and carried by the member 52, these lugs beingl preferably formed on plates felwhich are set into the threaded periphery 53 of the member 52 to be inset relative to the threads thereon and held in place, as by the screws 75. rlhe member 64 is slide-ble lengthwise on the member 52 `for moving` the cooperating clutch elements referredI to into and out of interlocking;` position to connect tosrethen or disconnect. the members 52 and 64E 'For driving the former from the latter at will. The member 64 is provided with a flange 76 equipped with plungers Z7 which lgruidingrly extend into sockets 78 provided in a 'face olt a Worm wheel 79 surrounding' the member Gil: and splined thereona to cause the member '54 and the worin wheel 7 9 to rotate together. the latter abutting' the inner face ot the ring* 66. The plungers Z7 have reduced portions 80, and are provided with shoulders 77 these plungers extending` parallel with the axis ot the worm wheel 79 and guidinelv extending` into openings Sl'in the wheel 75L the sockets 78 containingv coil springs 82 which surround the plunejers 77 an d by bearat their opposite ends against the bases ot the sockets .78 and the shoulders 77a. yielding/'ly 'torce the member G4 to the rig it in Fig, 6 to a position in which the clutch device hereinbefore referred to clutches the members 52 and 64. together when the notches 72 and lugs 73 are in alinement.

Means are provided for controlling` the throwing of said clutch into and out of p position.` these means.y chown. ,fr iornied ot a lever 3? tulerumed tween its ends ou a pin di siuaiorted in brutal-ets extendingv from the housing {ifi} the lower end ot this lever being `iorkod to provide the curved arms 36 which are equipped with inwardlgs-extending' rollersl Si yiournaled thereon tlirougrh the medium of the headed pins S8, these rollers extent ine; into the annularly recessed portions 7l ot' the ringl l0 and bearing against the inner side of. the latter as represented (Fig. 5). it being' understood that in the swingingr ot the lever 88 in clockwise direction in Fins. 5 and 6, the member 6% is shifted to the lett in these figures to separate the members ol the clutch device described.

The worm wheel 79 is driven through tlv .medium of a Worm S9 secured to shaitt 91') liournaled in the housing' i6 and shown as provided with hand wheel 91 tor rotating it. ln this connection it may be stated tiat the machine shown is adapted to he operated through the medium ot' the shaft 9U. rotatcdby hand, but will` be readilyv under stood that. it desired, it muy be driven troni a power device and, where desirable, anyY suitable means for automaticalh7 arresting rotation oli the shatt thus driven. and after a die has been threaded, may be pro vided.

Through the medium ot the drive inecha nism just referred to the member which. as hereinbetore explained supports the dieblank 25 to be operated on, is caused to be rotated in clockwise direction in Fic' 3 to cause it to make a` practicallyv compl "evolution, the member 52 `gradually nim ing); inwardly, viz., to the left in Fig'. G, into the housing` i6 bv reason oll its threaded counction therewith. the leiLQ't/luvise travel ot the nieinber 52 beingA equal to the dt nce between any two adjacent portions of the thread The work-holder shown conn prises the plate 6l provided on its outer tace with a plurality ot bosses 92 pretert'ibly dis'- posed inV rectaiurular arrangement around the opening- 97% in this plate and agiainst which the blank is adapted to bear at face thereof. At one side oi the openiu f 9?; the plate 61 is provided with laterallyef'eotlingg lug' 94 in the forni of a bar equipped with bosses 95 spaced apart and against which the die-blank bears at an. educ thereof. The plate 6l is also pr vided with a. laterali:tf-extending portion 96 preferably disposed a right angle to the bar 911- and provided with a. lateralljv-extendingf boss 9T against which the die-blank bears et another edge thereof. The extension 96 is slotted as indicated at 98 to provide the thi-ee lugs 99` 100 and 101 through which a pivot pin 102 extends, the inner tace of the plate 103 being provided with bosses 105 prenten ably disposed in rectangular arrangement 'thereon and in line with the lugs 92, respectively. '.he opposite end of the plate 103 contains a slot 106, the outer ace ot the plate at the portions thereoil ilanking this slot tapering in the direction as indicated at 107 (Fig. 7), rlhis portion ot the plate 103 cooperates with a. clamping device shown as formed oit a rod 108 pivoted at its inner end on a pivot pin 109 confined in ears 110 extending laterally `from the plate 61. The rod 108 is formed with a head 111 at which the pivoting referred to is effected, the edge portion of this head which opposes the dieblank 25, when the latter is introduced into the holder, being preferably in the form of a cam as represented at 112. rihe rod 108 extends through the slot 106 and is provided at its outer, threaded, end with a nut 113 preterabiy having a curved inner end portion as represented at 114 which bears against the tapered surfaces 107 of the plate 103, The plate 61 is also provided on its outer face, and diametrically opposed tothe bar portion 94, with a pair ot laterally-extending ears 115 containing a pivot pin 116 which extends through, and Jforms a pivot `tor, a rocking member 117, the tree edge of which is preferably curved as represented at 118, the member 117 being outwardly pressed by a spring 117a. The member 117 cooperates with an operating device therefor shown as formed of a rod 119 extending loosely through an. opening 120 in the member 117 and engaging the outer face of this member at a shoulder 121 on the rod, this rod having threaded engagement at its inner end With. an opening 122 in the plate 61. 1t may be here stated that in the positioning of the dieblank in the holder, the operator, assuming the actuating device formed of the rod 108 to be swung outwardly, introduces the die-blank 25 into a position wherein it rests upon the bosses 95 and against the boss 97. The operator then swings the plate 103 toward the die-blank and the operating member formed ot the rod 108, into a position wherein the rod portion extends into the slot 106 and the nut 113 opposes the tapered surface 107 of the plate 103. Upon tightening the nut 113 on the rod 108 the engagement of the nut with the tapered surface 107 operates to swing the rod 108 in counterclockwise direction in Fig. 7 thereby causing the cam surface 112 to ride against the adjacent edge of the die-blank and force it rigidly up against the boss 97, the manipulation of the nut as stated also serving to firmly force the blank against the bosses 92. The'operator then swings the member 117 toward the plate 61 and into engagement at its surface 118 with the adjacent edge ci the die-blank 25, to exert a clamping force against this edge of the plate, by screwing the rod 119 into the plate 61, the construction of work-holder described operating to very tirinly hold the die-blank in position on the member 52. 1n the machine illustrated, the dieblank is caused, during the cutting ci each segment 27, to be bodily shifted to the left 'in Fig. 3, thereby producingthe backing off, or relieving, or the die at each of its segments, thel die-blank being shifted in the opposite direction to cause the die-blank and the milling device 31 to occupy the necessary relative positions for cutting the next segment to c"backed orf condition, before the next segment has moved into engagement with the milling device, a description of the means shown for this purpose being as tollows:

Mounted on the base 32 at the lett hand end thereof in Fig. 3, is a block 123 provided with a depending tongue 124 located within a groove 125 in the upper surface of the base 32 whereby .this block may be guidingly adjusted lengthwise of the base, the block 123 being provided with set-screws 126 :t'or securing it in adjusted position. The block 123 is provided with upwardlyextending ears 127 spaced apart and into the space between which the lower end of a lever 128 extends, this lever being pivoted to the ears through the medium of a pivot bolt 129. The lever 128 is pivotally connected, through the medium of a pivot bolt 130, with the outer ends of a pair ot links 131 spaced apart and arranged at opposite sides of this lever, the inner ends of these links being located at opposite sides of an ear 132 provided on, and extending laterally from, a block 133 rigidly secured,as b v means of the screws 134, to the housing 46, the links 131 being pivotally connected with an ear 132, as through the medium ot a pivoting bolt 1136. The upper end of the lever 128 is provided with a stud 137 e2:- tending laterally therethrough in opposite directions on the protruding ends of which rollers 138 arel journaled, these rollers eX- tending into slots 139 provided in the biurcated head port-ion 140 of a lever 141, pivoted at its opposite end, as indicated at 142, to an upwardiy-extending ear 143 provided on the casing 46, the side arms of the bifurcated head 140 being spaced apartand the lever 128 extending between these arms. r1`he lever 141 is preferably formed of the bar 141n a bar 141b and a block 141C interposed between the bars 141@ and 141D, these parts being held together by a pin 144 and a bolt 145. The block 141c extends short of the right hand end of the'lever 141 in Fig. 3 whereby this lever presents at the extremities of its bars 141a and 141b spaced portions between which the lug 143 extends and through whichthe pivoting bolt 142 passes. The location of the' opposite side walls of raaaaea the slots 139 and which are engaged by the i s snch that as the lever 141 is i i'uicruni 142 it will produce a rocking of the lever 128 on its tulcrum 129. the walls referred to ci these slots being preferably of are shape and struck trom a center preferably a slight distance above the axis of, and in a direct. Vertical line with, the axis of the pivot 142 as shown in the drawings (F E), wherebjfzf' in the upward moy'vementof the lever 141 the lever 12S is snifted to the rightin Fig. 3 and on the` downward movement ot' the lever 141 the lever 128 is shifted to the left in this ligure. the means shown ter actuating the mechanism just described being as follows: Tournaled in the housing 50 is a siatt 146 equipped with a hand wheel 147 and carrying a pinion `148 rigid thereon which is in mesh with the gear 54, the shaft 146 carrying-'a disk 149 in which apin 150 arranged eccentric `of the axis of the shaft 146, is secured. Pivoted at its lower end on the pin 150 is a link 151. its upper end being pivotally connected, by means of the pivot pin 152, with the lever 141 at a point between the ends ot the latter, whereby in the rotation of the pinion 148, by the rotation of the gear 54. the link 151 will be caused to be bodily raised and lowered and the lever 141 to be rocked, the proportions of the pinion 148 and gear 54 being such that the shaft 146 will make tour complete revolutions with each revolution ot' the gear 54, where the die-blank to be operated on is provided with tour segments to be threaded as in the case ot the blank shown, thereby to cause the sub-base 41 and the parts carried thereby to make four complete reciprocations with each complete rotation ot the work-holder.

The gear 54 is provided at its opposite tacos with projections 153 and 154 which may be aiilorded by providing the. gear 54 with a pin extending therethrough and projecting at its ends beyond the opposite faces of the gear, the projection 154 being` adapted to cooperate with a stop surface 155 on the tace of the ring 58 opposing the gear 54, and the projection 153 being adapted to cooperate with a stop surface 15G provided on the housing 46 and extending into 'the recess rlhe stop surfaces 153 and 154 are provided for the purpose ot limiting the rotation of the member 52. and consequently the work-holder, in both directions, the structure being` designed to permitthe meniber 52 to make practically one compl-cte rotation only irom initial, starting, position. In the starting position the projection 154 engages the stop surface 155 as shown in Fig. 10, and in the rotation ot the gear 54 one revolution, during which operation the gear 50 and the parts connected therewith more to the lettV in 5 by reason ot' the rotation or" the member 52 within the threads oi the housing' 5U, the projection 1.1115 engacfes 'he stop 'race 15o. vThe operation of the machine is as follows: s- .-iuniing that the parteI oi" the machine are in normal position and the work-holder is empty, the operator introduces the die-blank to be operated on. represented at 25, into the holder seal it upon the stop surfaces 95 and against the stop sui-tace 9'?. rllhe piroted clamping plate 10?; is then swung at its hinge connor/ion with the membeL toward and into contact with the onterniost tace ot the die-olank, nd the pivot rod 108 then swuno` to a po ltion in which it extends into the slot in the piate rif" e nut 117% is then screwed upon the rod 1% and trm'ard the plate 105 in which operation the iut forced against the tapered surface 10? oi" said plate with the result ot causing the rod 10S to swing to the rignijht in 2. T which not only i'orces the plato 103 into rigid clamping engagement with the die-blain. 25 to thus firmly clamp it between this plate and the member 61, but also, by reason oi. the clamping action exerted by the cam member 111 on the rod 108 and engaging the adjacent edge oi the die-blank, forces the latter rigidly against the stop surface 97 thereby clamping the plate firmly vin a lateral direction. rEhe operator then, by manipulating` the screw 119, wed` member 11T against the upperl edge ot die-blank which firmly clamps the latter tween the member 11'? and the stop sur- 'lace 95.

Assuming the milling device 31 to 'be rotating, the operator, to effect the threadcutting;` operation, rotates the shaft 9() which, in turn, through the ined:l in ot the worin S9. rotates the worm w reel 79 and. througrrh the medium ot the clutch mechanism described. rotation ot the member 52 carrying the work ettected.` the work rotatinn` in clockwise direction in Figs. 3, 8, 10, 12 and 13 and the milling device being shown as rotating upon its axis in the opposite direction indicated by the arrows in 12 anl 1?. In the normal position oi the machine, the segment to be rst threaded, riz. the lowermost one at the lett hand side oi Fig. 10, is below the plane ot the sitting` members oit the milling.` device and the crank-pin 150 is in such position that axis attends to the right ot, and below. the axis of the shaft 146, viewing the machinfI in 3, 12 and 13, in which position oi" the parts the housing` 4G and the parts carried thereby are disposed at a point intermediate the extremities or. their stroke. Rotation ot the shaft 90 as stated rotates the shaft 146 in counter-cloclwrise direction in Figs. 12 and 13, thus causing the lever 141, through the link connection 151 to be rocked on its pivot 142 in clockwise direction (Fig.

3) With the result, by reason of the engagement of the rollers 138 with the slotted portion oi' the lever 141, o1' swinging the lever 128 in clockwise direction (lfig. on its 'ulcrum 129, thereby slowly shifting the housing Li6 and the parts carried thereby to the right in Fig. 3. The shifting ot the housing, as stated, continues until the segment referred to reaches substantially the position shown in F ig. 12, the continued rotation ot the shaft 90 operating through the linlr connection 151 to swing the lever 1.41 around its pivot 14:2 in counter-clockwise direction in Fig. 3 with the result ot causing the lever 128 to swing in counter-clockwise direction on its plv t 129 and thereby slowly shift the housing 4G, and the parts carried thereby, to the left in 3, the shitting of the housing as last stated continuing throughout the time that the segment last referred to continues in engagement with the milling device (see Fig. 15), With the result of causing the thread cut on this segment to recede from the center opening of the blank, thereby producing what is lrnoivn as a relieved, or backed oli, condition of the thread.

The various links and levers described and forming the mechanism by which the housing 46, and the parts carried thereby, is reciprocated as stated, are so proportioned and connected together with the housing 46 and base 128, as shown in the drawings, that this mechanism .vill operate smoothly to perform its itunction and by the exertion ot compara tively slight turning force applied to the shaft 90. At the conclusion of the cutting ot the thread on the segment last referred to, and before the next segment 27, by the continued rotation lot' the shaft 90, is moved into engagement with the milling device, the crank-pin 150 ivill have again moved to the position occupied thereby in the normal position of the machine hereinbeiore re ferred to, and the 1work-holder will thus have become repositioned, by moving to the right` in 3, tor causing` the segment last referred to to be operated on by the milling device in the continued operation oit the machine explained oit the segment first referred to, the crank-pin 15() making tour complete revolutions for cach revolutiono't the Work-holder.

Upon the conclusion ot the cutting of this last-reterred--to segment, the housing again sli .ts to the right in ilig. 3 While the next, third, segment is being carried into a position to be operated ou by the milling device. this third `segment being cut as eX- plained ci the first segment, and during the shitting the housing Li6 to the right for the fourth time, and partial rotation ofthe member 52, the Fourth segment is cut.. it the conclusion ot the cutting ot these four segments the member 50 will have completed practically a complete revolution and in doing' so i'urther rotation thereof is arrested by the engagement of the stop 153 with the stop 156iI lnasmuch as the member 52 en gages at its thread 03 with the threaded portion 51 of the housing 46, which thread is ot the same pitch as the threadto be cut on the die, the member 52 will move lengthwise in a singlerotation, a distance equal to the pitch ot the thread 5l, and in adjusting the boss l5 on the sub-base Ll1 at the hinging shaft 43, before the cutting operation begins, to cause the die-blank to extend at an angle to the airis of the milling Vdevice corresponding with the angle of the lead of the thread desired to be i'ormed on the segments oi the blanlneiitends, such threads are caused to be accurately formed. Y

F rom the foregoing itwill be understood that the tour segments oi' the die-blank are out, to thread the same, in succession, and that each is in backed off, or relieved, condition. f Y

The mechanism is so constructed and arranged that the milling device operates to cut the segments in a direction toward what becomes, in the finished die, the cutting edges thereof or, in other Words, from the back toward the tro-nt, or cutting edge, ot the segment, as will be clear from the drawings (see Fig 13), this being of advantage as the cutter elements of the milling device during the cutting` ot those portions of the segments which cutting edges the threads extend in the finished die, out alesser body of. metal than they Would if the reverse .operation occurred, thereby causing the finished threads to present clean cutting edges.

ln the particular construction illust-rated provision is made for causing the threaded opening in the die to taper Jfrom its front tace, viz., the 'tace ot' the die which would extend at the right hand side or" Fig. Gand at which the die in use is applied to the article on which the thread is to be cut, toward its rear iace, viz., the portion ot the die which is the last o operate on the article to be threaded by the die, and this is accomplished in the particular illustrated embodiment shown by disposing the guide rib 39 obliquely relative to the axis labout which the milling device rotates.

,lnasmuch as the Workinclines' relative to the milling device to produce the tapered threaded opening` in the die, it is desirable to provide the cutter elements on the milling device in such Jform that instead of the converging cutting edges of the cutter elements extending at equal angles to the axis of the cut-ter they shall extend at slightly different angles thereto to offset for the obliqueness of the angle between the face of the Work and the axis ot the milling device and out a thread the converging edges ot which shall extend at the same angle to the axis of the hnished die atter a die-blank has been threaded, as described.

The operator, to return the member 52 to normal position in the housing elli, throws the lever into a position in which the cooperating` clutch elements 'T2 and T3 are out of mesh thereby permitting the member 52 to be tnrned at its threaded connection with the housingi6 throughout pre "rally a complete revolution to normal cf' dition, in which. the member moves to the right in l? t3, by rotatingi the hand Wheel lel.

lt will be understood from the drawings and from the foregoing description that the machine is adapted, by reason of the adjustments provided therein, for use in the forming of dies the internal diameters of' which vary.

lt will also be understood that in the cutting of threads on dies of different internal diameters, the angle at which the Work is caused to extend relative to the axis of the milling' device, determined by its adjustment on the hinge-pin 43, should be varied to cause this angle to correspond With the angie of the lead of the thread to be produced.

Referring now to the embodiment of my invention shown in Figs. 11i to 17 inclusive, and relating to the mechanism for shifting the sub-base 411 and the parts carried thereby to eil'ect the backed oil condition of the threads of the segments, the mechanism ot these igures isthe same as that oit the preceding figures except that, instead of providinga single lever like the .lever 141 with the pin and slot connection between it and the lever 12S, l provide a toggle lever represented at 200 and formed of the tivo linksections 201 and 202 pivotally connected by a pin at 208, the outer end of the link-sec- "ion 201 being pivotally connected with the ipper end of the lever 12S, by means ot the l.iivot piu 201i, and the outer end of the linksection 202 being' pivotally connected at the "iin 205, to an upstanding ear 206 rigid With the housing' 46. The link 201 is preferably formed ot tivo tlatvvise opposed sections 201@ which straddle the lever 28 and the link 202 is preferably formed of tivo link-sections 202n and an intermediate block 250 secured to the sections 202a by pins 251, one end oi.E one of the link sections 202n extending' between the adjacent ends of the link scctions 2011L through which and the other oit' the link-sections 202"l the pivot pin 203 extends.

r Phe various links and levers described and formingY the mechanism by which the housing' 46, and the parts carried thereby, is reciprocated as stated, are so proportioned and connected together With the housing et() and base 123 as shown in the drawings, that this mechanism will operate smoothly to perform. its function and by the exertion nxthout departing from the spirit ot' my invention, and the invention may be embodied in, other i'orms of structures than those shown.

7ifi/That l claim new, and desire to secure by Letters Patent, is:

1. ln a machine oi' the character set i'ori'h,

the combination of a base member, a sec ond member movable on said base member. and means` tor moving` said second member on said base member comprising mechani n formed oi relatively mo fable elements operatively engaged together, said mechanisir operatively engaging said base member aan said second member at opposite sides ot toe point at which said elements operatively cng'age each other, and means for etlecting` relative movement ot said elements.

2. ln a machine of the character set forth, the combination of a base member, a second member movable on said base member, aud means for moving said second member on said base member comprisingy mechanism toi-med of relatively movable elements operatively engaged together, said inechan' o operatively engaging said base member said second member, and means operatively enga,gjii'ig` said mechanism between i points of connection with said base member and said second member, 'ior etliectinji relatiif movement of said elements.

3. ln a machine ot the character set tortli, the combination of a base member, a sei'- ond member moif'abley on said base niemlziei. and means tor moving' said second mem on said base member comjirisina' mecban wiz: 'tormed oi relatively movable elements operatively engaged together` said mechanism .operatively engaging` said base member and operatively eng-aging, by a plurality olf said elements., with said second member a pinrality of points, and means for eiliectine' relative movement of said elements.

4. ln a machine of the character set forth, the combination ot a base member, a second member movable on said base member, and means for moving` said second member on said base member comprising mechanisn'i formed ot relatively movable elementsy operatively engaged together, said mechanism operatively engaging; said base member and operatively engaging', by a plurality ot said elements. With said second member at a plurality oi points, and means operatively engaging said mechanism between its point ot connection with said base member and one of its points or" connection with said second member, for etliectingr relative movement of said elements.

5. ln a machine of the character set forth, the combination of a base member, a second member movable on said base member, and means for moving Said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, one of said elements being a lever fnlcrumed on said base member with a connection to saidy second member, and another of said elements operatively engaging said second member at a point non-coincident with the point of engagement of said connection with said second member, and means for effecting relative movement of said elements.

G. in a machine of the character set forth, the combination of a. base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, one of said elements being a lever fnlcrnmed on said base member' .vith a connection to said second member between the. ends of said lever, and another of said elements operatively engaging said second member at a point non-coincident with the point of engagement of said connection with said second member, and means for effecting relative movement of said element. 1

7. In a machine of the character set forth, the combination of a base member, a second member movable on said-base member, and means for moving said second member on said base member comprising mechanism formed of relatively7 movable elements operatively connected together, one of said elements being a lever fnlcrnmed on said base member with a connection to said second member, and another of said elements operatively engaging said second member at a point non-coincident with the point of engagement of said connection with said second member, and means operatively engaging said mechanism between the points of engagement of said mechanism with said second member, for effecting relative movement of said elements.

8. ln ar machine of the character set forth, the combination of a base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, one of said elements being a lever fnlcrumed on said base member with a connection to said second member between the ends of said lever, and another of said elements operatively engaging said second member at a point nonvcoincident with the point of engagement of said connection With said second member, and means operatively enga-ging said mechanism between the points of engagement of said mechanism with said second member, for eifecting relative movement of said elements.

9. In a machine of the character set forth, the combination of a base member, a second member movable on said base member, and means for moving said second. member on said base member comprising mechanism formed of relatively movable elements operatively connected together including levers pivoted to said base member and said second member, respectively, and operatively connected together, with a connection between said second member and the one of said levers pivoted to said base member, and means for effecting relative movement of said elements.

l0. in e. machine of the character set forth, the combination of a base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together including levers pivoted to said base member and said second member, respectively, and operatively connected together, with a connection between said second member and the one of said levers pivoted to said base member, the operative connection between said elements being between the connections of said levers with said base member and said second member.

1l. ln a machine of the,- character set forth, the combination of a base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, including levers pivoted to said base member and said second member, respectively, one of said levers presenting a cam surface engaged by the other of said levers, and means for actuating one of said levers.

l2. ln a machine of the character set forth, the combination of a base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, including levers pivoted to said base member and said second member, respectively, one of said levers presenting a cam surface engaged by the. other of said leversand means for actuating the one of said levers presenting said cam surface.

13. In a machine of the character vset forth, the combination of a base member, a second member movable on said base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, in-

cluding levers pivotedto said' base member and said second member,respectively, the one of said levers pivoted to said second member presenting f a cam surface engaged bythe other of said levers, and *means* for actuating one of saidlevers.

111-. ln a lmachine of the character set forth, the combination of a basemember, a second member movable on said base meniber, and meansfor movingsaid second member-on Asaid base member comprising mechanism formed of relatively vmovable elements-operatively connected together, i including levers pivoted to said base member and saidsecond member, respectively, the V one of said levers vpivoted to said second member presenting a cam surface-engaged by the other of said levers, and means for actuating said last-referred-to .,lever,

15. In a machine of the character set forth, the combinati-@nef a base member, a second member movable on said base member, and means for moving said second member on said b ase member comprising mechanism formed of relatively movable elements operatively connected together, 'fincluding levers pivotedto said base member and said second'member, respectively, with the connection between said second member and the one o-f said levers pivoted to said base member, one of said leverspresenting a cam surface engaged by the other ofV said levers, and means for actuating oneofsaid levers.

1G. In a machine of the character set forth, the combination of a. base member, i second member movable on said base member, and means for moving said second member on said .base member comprising mechanism formed of relatively movable elements operativelyy connected together, including levers pivoted to said base member and saidsecond member, respectively, with the connection between said second member and the one of said levers pivoted to said base member, one of said levers presenting a cam surface engaged by 'theother of said levers, and means .for actuating one of .said levers presenting said cam surface.

17. In va machine of the characterv .set forth, the combination .of av base member, a second member movable on said base-inember, and means for moving said second member on said base member .comprising mechanism formed of relatively movable elements operatively connected together, includingl levers pivoted to said basemember and said second .membei respectively, With a `connection between said second `member and the one of said levers pivoted to said base member, the other of said levers presenting a cam surface engaged by the one of .said levers connected .With said base member, and means for actuating one of said levers.

1S. 1n a .machine of the character set forth, the combination of a base member,

a second `member movable on said-base member, and means for moving said second member on said base member comprising mechanism formed of relatively movable elements operatively connected together, including levers pivoted to said base `member and said second member,A respectively,#with a connection between .said econd member and the one of said levers pivoted to said base men'iber, the other of-said levers `presenting cam surface engaged by the oneofsaid levers donnected With said base ngember, and means for actuating-said cam-equipped lever.

19. 1n a` machine -of VJthe character set forth, the combination ofabase member, a second member movable on said base member, andmeansffor moving said second member on-said base-member comprising mechanism` formed of relatively movable elements operatively connected' together, including levers -pi-voted to said base member and said seconchmember, respectively, one of said levers presenting a vcannsurface of general curved lform Aeccentric ofA the -aXisA about Which -said lever moves, `said cam surface being engaged bythe other of -said levers, andmeans for actuating said cam-equipped lever.

20. In amachine of the character set forth,` the combination ofa base Ymember,

a second member movableon 4said base member,I and means for movingy said second member on `said basemember comprising mechanism y'formed of relatively movable elements operatively connected together, including levers-pivoted toisaid-base member and said secondinember, respectively, the-one of said levers which ispivoted `tosaid second member prcsciltinga cam surface of general curvedform, extending ecce-ntrica'lly-of the `anis aboutgvvhich said lever operates, said cam suriace being engagedl by the other of said levers, and means 'for actuating ,said cam-equipped lever.

:21. 1n a machine ofthe character set forth, lthe ,combination of4 al base member, a second member movable on said basemember, and means for moving said second member on said base Vmember comprising mechanism formedof relatively movable elements 'operatively connected'together, including levers pivoted to said base member and said secondinember` respectively, with a connectionA between said second member and the one of said levers pivoted to said base member, the one of said levers pivoted to said second member containing` a camy surface of ygeneral curved form. extending eccentrically ofthe axis about .which said lever operates, said cam surface being engaged bythe other of said levers. and means for actua-ting said cam-equipped lever.

22.111 a machine for cutting threads on an object, 'the combination of a holder-mem- 

